On minimal models of elliptic threefolds.
On the (-1)-curve conjecture of Friedmann and Morgan.
On the connectedness of the locus of real Riemann surfaces.
On the difference between real and complex arrangements.
On the Euler Characteristic of Complex Algebraic Varieties.
On the Euler characteristic of fibres of real polynomial maps
Let Y be a real algebraic subset of and be a polynomial map. We show that there exist real polynomial functions on such that the Euler characteristic of fibres of is the sum of signs of .
On the Euler characteristic of the link of a weighted homogeneous mapping
The paper is concerned with an effective formula for the Euler characteristic of the link of a weighted homogeneous mapping with an isolated singularity. The formula is based on Szafraniec’s method for calculating the Euler characteristic of a real algebraic manifold (as the signature of an appropriate bilinear form). It is shown by examples that in the case of a weighted homogeneous mapping it is possible to make the computer calculations of the Euler characteristics much more effective.
On the Euler number of an orbifold.
On the Fundamental Group of a Unirational 3-Fold.
On the Genus of Varieties of Codimension 2 in Projective Space.
On the homology of algebraic varieties over real closed fields.
On the Hurwitz scheme and its monodromy
On the number of non-equivalent differentiable structures on 4-Manifolds.
On the Picard number of a complex projective variety
On the Ramification of Branched Coverings of IPn.
Open surfaces with non-positive Euler characteristic
Orientation-reversing homeomorphisms in surface geography.
Perfect stratifications and theory of weights.
In this paper we emphasize Deligne's theory of weights, in order to prove that some stratifications of algebraic varieties are perfect. In particular, we study in some detail the Bialynicki-Birula's stratifications and the stratifications considered by F. Kirwan to compute the cohomology of symplectic or geometric quotients. Finally we also appoint the motivic formulation of this approach, which contains the Hodge theoretic formulation.
Positivity results for Euler characteristics of singular surfaces.
Postulation of Canonical Curves in IP3.